Boom structure



Jan. 13, 1959 G. L. POFFENBERGER BOOM STRUCTURE 5 Sheets-Sheet 1 Filed Sept. 28, 1956 VE/Y 70A; 6. E/VN 4. POFFE/YB-RGEP.

4 7'70/P/YEK Jan. 13, 1959 G. 1.. POFFENBERGER BOOM STRUCTURE 3 Sheets-Sheet 2 Filed Sept. 28, 1956 Q um 2 //V l/E/VTOR 6L E/YN Z. POFFfNBERGEk ATTOR/YEK m Q Q.

Jan. 13, 19 9 G. L. POFFENBERGER ,86

BOOM STRUCTURE Filed Sept. 28, 1956 3 Sheets-Sheet 3 //V VE/YTOR 5LE/Y/Y Z. POFFENBEPGEP Unitfd tates Patent BOOM STRUCTURE .Glenn L. Poifeuberger, Altoona, Iowa Application September 28, 1956, Serial No. 612,680

9 Claims. (Cl. 212--8) pMy invention relatesto improvements in boom structures and one of the important. objects contemplated herein is the provision of improved means relating to the elevation of the boom.

:More particularly it is an object of this invention to provide a .boom that is longitudinally extensible and is progressively elevated when being extended.

Afurther object inhering in this invention is the provision of fixed guy lines in association with the extensible portion of -.the boom for effecting the elevation of the :boom.

Other objects and advantages 'of this invention reside in the details of construction and correlation of the variious'parts and will be apparent as-the description proceeds.

This invention consists of novel parts and combination of-parts to be hereinafter described whereby the objects .r'et forth are attained, as pointed out in the claims, and illu'strated in the accompanying drawings, in which:

=Fig. Us a side elevational view of this invention,

Fig. 2 is a top view thereof,

Fig. 3 is a cross sectional view taken on the line 3--3 ofFig. 1,

Fig. 4 is an enlarged perspective view of the control level used in the operation of the friction drive wheels, and,

Fig. 5 is a diagrammatic side view showing the boom in various positions of elevation.

Referring to the drawings a supporting frame consists of the parallel spaced H beams and 12 which are mounted at their rearward end on-the cross beam 14. To the forward under side of beams 10 and 14 are .are secured the short lengths of H beams 16 and 13 respectively, which support the transversely arranged tubular member 20. The tube or pipe 20 is parallel to cross beam 14 and is secured through the Web portion 22 of the beams 16 and 18. Both members 14 and 20 project outwardly from beams 10 and 12 and serve as bracing for beams 10 and 12 together with bracing 24 and other apparatus mounted thereon as will later appear.

The boom assembly indicated generally at 26 is mounted to member 20 and comprises a tubular member 28 rotat- ;ably encasing pipe 20 and extending between the inner .sides of the web portions 22 on the short beams 16 and 18.(F.ig. 3). Integrally secured to and projecting perpendicular ly therefrom in a forwardly direction is the boom 30 which can be raised'and lowered as will later appear by tube 28 turning about the longitudinal axis of pipe 20. The boom 30 is designed for telescoping and for this purpose has the outer section or casing 32 and inner section or beam 34. Telescopic movement is provided by hydraulic means and for this purpose section 34 is fitted to section 32 was to be extensible from and retractible within the same in a manner similar to that of a hydraulic jack .as is well known in the art. Brace members 36 and 38 extend between the forward end Joflthe outer casing 32 at opposite sides thereof to the respective tubular iportions 40 and 42 that are rotatably 2 mounted to the respective projecting portions of pipe '20. Tubular members 40 and 42 are integrally or otherwise firmly joined withbraces 36 and 38-and rotate about of=post 44- and a cable or guy line 52 extends from ahook 54 atthe upperend of boom section 34 over pulley 50 toward the rear and'then forwardly anddownwardlybelow it to a ring 56 (Figs. 1 and 2) which is engaged with a cable 58 attached at respective ends to theeyes 60 onthe respective braces 36 and 38. Cable 58 merely serves as a bifurcated extension of cable 52 which is of a fixed length from-the top of the boom, around pulley 50 to the braces 36 and 38.

At the rear of frame members 10 and '12 just forward of cross beam 14 is mounted a motor 62 on suitable supporting bracing 64. Shaft 66 on motor 62 carries a pu1ley68, on the outer side of beam 12 which connects by belt drive 70 to a pulley 72 on the same side of beam 12and nearer the forward end thereof. Pulley 72 is arranged for driving shaft 74 disposed transversely of beams 10 and 12 in bearing members 76 and 78 and on the other end of shaft 74 on the outer side of beam '10 is the friction drive wheel 80. To the rear of wheel 80 is another drive wheel 82 for operation thereof which is operatively arranged on shaft 84- that is disposed parallel to and spaced rearwardly from shaft 74.. Shaft .84 is mounted. tobeams 10 and .12 by the respective bearing members 86 and 38. On a higher plane than and intermediate shafts 74 and 84 and parallel thereto ,is shaft 90 arranged in bearing members 92 and 94 on the respective beams 10 and 12. Shaft 90 carries a cabledrum 96 and a gear member 98 which cooperates with a pinion gear 100 on shaft 84 in a well known manner. Shaft 84 (Fig. 1) is provided with an eccentric bearing 102 which is attached the lever 104. A manually operable lever handle 106 is rotatably connected to lever 104, and extends toward the forward end of beam 10 where it' is journalled in a brace 108 attached to beam 10 (Fig. 4).. The free end of lever 108 carries a handle grip 110 and spaced from grip 110 is a plurality of teeth or notches 112 which are engageable respectivelyby a spring-arm or pawl .114 mounted to brace 108. Levers 106 and10'4 are designed to move drive wheel .82 forwardly on its eccentric'into engagement with drive wheel 80 or rearwardly into engagement with a brake shoe 116 mounted to the outer side of'beam 10 as shown in Fig. 1. Notmally, lever 106 is held against moving longitudinally of beam 10 by the engagement of pawl 114 with one of the notches .112. However, by manually rotating lever 106 about its longitudinal axis, notches 112 are moved away from pawl 114 whereby lever 104 can be moved as desired. When this is done, lever 106 is rotated back unti pawl 1114 again engages the proper notch 112. a

On drum 96 a cable 118 is wound in the usual manner and extends to the forward end of the boom where it is reeved over pulley 120 and carries a hook 122 or other suitable load engaging device. A pump 124 for providing hydraulic pressure is mounted tobeam 10 .just behind pipe 20 and connects by conduit 126 to a control box 128. Box 128 in turn is connected by conduit :13!) .to boom section32 andto conduit 132 (Fig. 1) which runs from the forward end of boom section 34 as a return. Pump 124 is also connected by a supply conduit 134to reservoir tank 136 mounted on beams 10 and .12 behind shaft '84, and conduit 138 connects tank 136 to control box 128. The above structure for supply of fluid and circulation between the supply tank, pump, control box 3. and the boom is well known in the art and no invention is claimed in such hydraulic pressure arrangement per se. Pump 124 is operated from drive wheel 89 and for this purpose a pulley 140 operatively associated with the pump is connected by belt drive 142 to pulley 144 on shaft 146. Shaft 146 is supported in bearing member 148 and carries a friction drive wheel 150 (Figs. 1 and 2) disposed normally for engagement with wheel 80. Bearing 'member 148 is secured by a clamp 152 to a rod or shaft 154 which in turn is rotatably mounted on beam 10. A handle 156 on rod 154 allows it to be manually rotated whereby shaft 146 with pulley 144 on one end and wheel 150 on the other can be elevated in an art away from wheel 80 to disengage the drive connection therebetween. In this way the pump 124 need not be in operation at all times when the drum is and can be operated without the drum due to the arrangement of levers 104 and 106 previously described.

In operation, the drum 96 and load lifting cable 118 will function in a manner well known in the art. However, the cooperative relationship between the extensible boom and guy lines 52 and 58 is of novel structure which functions as follows. Lines 52 and 58 are of a fixed length as described and as shown connect at their respective ends to the upper end of the boom and lower portion of the boom braces 36 and 38 with the intermediate line length reeved over pulley 50 on the rear post 44 (Figs. 1 and By this arrangement the lowered or traveling position of the boom 34} is reached when hydraulic pressure is released and the lines 52 and 58 become taut as shown in the solid lines of Fig. 5. When the boom is to be elevated, hydraulic pressure is applied by suitable controls on box 128 with pump 124 operatively connected through drive wheel 150 to wheel 80. 'As boom section 34 extends from section '32 under hydraulic pressure, the resistance from cable 52 will cause the boom to rise as well as extend. Such action would be possible by merely securing pulley 50 to the top of post 44 but such an arrangement would limit the arc of movement by a radius determined by the distance between hook 54 on the boom and the top of post 44. To overcome this problem and allow the boom to fully extend, I have reeved cable 52 as described over pulley 50 and attached its lower end to the lower portion of the boom braces 36 and 38. Thus, as the boom is elevated, the point of attachment 60 of cable 53 to the braces 36 and 38 moves progressively closer to pulley 50 so that the radius of the are made by the boom is likewise progressively increased. As shown in the broken lines of Fig. 5, it will be observed how the guy lines 52 v and 58 control the elevation of the boom as described.

The type of structure which is shown here has proven to be extremely useful where overhead power lines are an obstacle to using a boom. This boom can be easily maneuvered beneath wires and then elevated as shown without danger of damaging the wires or requiring the work and expense in removing and replacing them.

It is pointed out that the structure as shown is mounted on a support or frame that will be carried on a suitable vehicle such as a truck bed or separate trailer. It will also be obvious that this unit when placed on such a vehicle for transportation can be mounted on a fixed base or a turntable without in any way departing from the principles shown.

It is submitted that the invention shown and described is aptly suited to achieve the purposes intended and is characterized by a combination of highly useful and mutually cooperating elements that combine their respective and proportionate functions in accomplishing the objects sought to be obtained.

It will be understood that the phraseology employed herein is for the purpose of description and not for limitation and that modifications and changes in the construction and arrangement of this invention can be made within the scope of what is claimed, without departing from the spirit and purpose thereof. It is thus intended to cover by the claims, any modified forms of structure or mechanical equivalents which may be reasonably included within their scope.

I claim:

1. In a boom structure, a frame, an extensible boom pivotally secured at its inner end to one end of said frame so as to project therefrom, an upstanding post on the other end of said frame, means for extending and retracting said boom, a pulley on the top of said post, and a guy line attached at its respective ends to the outer and inner end portions of said boom and reeved intermediate its ends over said pulley.

2. In a boo-m structure, a frame, an extensible boom pivotally secured at its inner end to one end of said frame so as to project therefrom, a brace pivotally attached at one end to said frame at each respective side ofsaid boom and connected at their other respective ends to the outer end of said boom, an upstanding post on the other end of said frame, means for extending and retracting said boom, a pulley on the top of said post, a'cable connected to and extending between said braces, and a guy line attached at its respective ends to the outer end of said boom and said cable and reeved intermediate its ends over said pulley.

3. In a boom structure, a frame, an extensible boom pivotally secured at its inner end to one end of said frame so as to project therefrom, an upstanding post on the other end of said frame, means for extending and retracting said boom, a pulley on the top of said .post, a guy line reeved over said pulley and attached at respective ends to the inner and outer end portions of said boom for effecting the elevation of said boom as it is extended, and the lower end of said guy line attached to said boom moving progressively closer to said pulley as the boom extends and rises to progressively increase the radius of the arc in which the boom rises as determined by the length of guy line between said pulley and the outer end of said boom.

4. In a boom structure, a frame, an extensible boom pivotally secured at its inner end to one end of said frame so as to project therefrom, an upstanding post on the other end of said frame, a pulley on the top of said post, a friction drive wheel mounted on said frame, means for driving the same, a cable drum on said frame, a cable wound thereon and reeved over the outer end of said boom, friction drive means operatively connecting said drum to said drive wheel, manual lever means for engaging and disengaging said friction drive means with said drive wheel, brake means engageable at times by said friction drive means, hydraulic means for extending and retracting said boom including pump means operatively connected to said drive wheel, means for selectively engaging and disengaging said pump means with said drive wheel, and a guy line attached at spaced points on said boom and reeved on said pulley.

5. In a boom structure, a frame having a forward and rear end, an extensible boom pivotally secured at one end to the forward end of said frame so as to project forwardly therefrom, means for extending and retracting said boom, and means for effecting the elevation of said boom as it is extended; said last means comprising a pulley at the rear end of said frame, and a guy line reeved over said pulley with its respective'ends secured to said boom in longitudinal spaced relationship thereon.

6. A device as defined in claim 5 in which said guy line is of a fixed length.

7. In a boom structure, a frame, an extensible boom pivotally secured at its inner end to one end of said frame so as to project therefrom, an upstanding post on the other end of said frame, means for extending and retracting said boom, a pulley on the top of said post, and a guy line reeved over said pulley and attached at its respective ends to said boom in longitudinal spaced relationship thereon for effecting the elevation of said boom as it is extended.

8. In a boom structure, a frame, an extensible boom pivotally secured at its inner end to one end of said frame so as to project therefrom, an upstanding post on the other end of said frame, means for extending and retracting said boom, a pulley on the top of said post, a guy line reeved over said pulley and attached at its respective ends to said boom in longitudinal spaced relationship thereon for eifecting the elevation of said boom as it is extended, and the lower end of said guy line attached to said boom moving progressively closer to said pulley as the boom extends and rises to progressively increase the radius of the arc in which the tween said pulley and the outer end of said boom.

9. In a boom structure, a frame having a forward and rear end, a boom assembly including an extensible boom pivotally secured at one end to the forward end of said frame so as to project forwardly therefrom, means for extending and retracting said boom, and means for effecting the elevation of said boom as it is extended; said last means comprising a pulley at the rear end of said frame, and a guy line reeved over said pulley with its respective ends secured to said boom assembly in longi- 10 tudinal spaced relationship thereon.

References Cited in the file of this patent UNITED STATES PATENTS 

